Air conditioning system utilizing refrigeration



March 4, 1941. s. M. ANDERSON AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION Filed Nov. 17, 1938 ON m 2 N m 7 x m u muwzmn 2 H monBEi z m M H U W I Tt N853 5.55m NN J E NM I E .3 z p N .WN M K 1 2 JAAfl/EL, M- ANDEIESOA/ w tfio M163 Patented Mar. 4, 1941 PATENT OFFICE AIR CONDITIONING SYSTEM UTILIZING REFRIGERATION Samuel M. Anderson Sharon, Mass., assignor to B. F. Sturtevant Company, Boston, Mass.

Application November 17, 1938, Serial No. 240,995

8 Claims.

This invention relates to air conditioning systems employing refrigeration and relates more particularly to air conditioning systems for passenger vehicles employing mechanical refrigeration.

The .usual air conditioned railway passenger car, is provided with an over-sized refrigerant compressor capable of supplying the refrigeration required under peak load. The compressor probably operates under peak load not more than ten .days of a year, although it operates under reduced load about five months of a year. It is also the practice to recirculate about 75% of the air through the air cooler for saving refrigeration. This results in the over-sized compressor being started and stopped by the car thermostat at frequent intervals, it being idle a longer period than it is in service. This frequent cycling of the compressor equipment is undesirable for the reason that it increases depreciation of the equipment. The continuous recirculation of the air also adds undesirable odors to the air.

I have determined that for a large portion of the time, the wet bulb temperature of the outdoor air is at or below about 70 F. under average conditions. I have also determined that when the wet bulb temperature of the outdoor air is not above about 70 F., the increased cost due to energy consumed, of supplying 100% outdoor air to the cooler, and of operating the compressor during longer periods and in fact, continuously if possible, is more than justified by the absence of unpleasant odors from the air, better control of humidity, and better air conditions.

5 I provide an air washer for cleaning and cooling the air, refrigeration compressor equipment, for

cooling the spray water, a car thermostat for starting and stopping the compressor, and a .wet

bulb thermostat in the outdoor air stream for adjusting the outdoor and recirculated air intake shutters for increasing the volume of outdoor air preferably to 100% when the wet bulb temperature of the outdoor air is at or below 70 F., and for decreasing the volume of outdoor air when the wet bulb temperature of the outdoor air rises 4 above 70 F.

Another feature of my invention resides in automatically reinvigorating the recirculated air when the controls act to supply it' to the conditioner. This is accomplished, for example, by irradiating the recirculated air with ultra-violet light for destroying bacteria, and/or by spraying into the recirculated air a substance such, for example, as pine oil for the purpose of imparting to the recirculated air the characteristics of outdoor air.

It is seen therefore that one object of my invention is to use larger volumes of outdoor air in the air conditioning of passenger vehicles, and 5 to operate the refrigerating equipment during longer periods than has been the practice in the past, and that another object of the invention is to reinvigorate the recirculated air to simulate outdoor air when it is not economically feasible 10 to use all outdoor air.

The invention will now be described with reference to the drawing which is a diagrammatic view of one embodiment of the invention.'

The air washer 5 is supplied with chilled water 1 by the pump 6 from the evaporator l. The compressor 8, driven by the electric motor 9, supplies the usual volatile refrigerant to the evaporator, through the condenser 10.

The car thermostat II is connected in circuit 20 with the motor 9 and the electric source l2 and starts and stops the compressor motor when the temperature is above and at respectively, the desired temperature.

The blower l3 draws outdoor air through the 25 shutters l4, and recirculated air from the passenger space through the shutters l5, and passes the air through the washer 5 into the supply duct H.

The shutters Hand l5 are adjusted by the mo- 30 tor I6 which is controlled by the thermostat it which responds to changes in the wet bulb temperature of the outdoor air. The thermostat is connected by the wires I9, 20, 2| and 22 in circuit with the shutter motor l6 andthe electric source l2 and acts when the wet bulb temperature of the outdoor air is at and below 68 F., to open the above described circuit causing the motor Hi to close the shutters l5 and open the shutters l4 so that all outdoor air enters the washer 5. During this period, the load on the conditioner is greater and the compressor operates for longer periods of time. The result however, is that the air is more comfortable, is odorless, and the humidity does not rise as it normally does during the more frequent ofi cycles of the prior systems.

When the wet bulb temperature of the outdoor air is above 70 F., the thermostat l8 closes the above described circuit causing the outdoor and recirculated air shutters to be adjusted by the motor Hi to supply, for example, 75% recirculated air and 25% outdoor air. At the same time, the converter 23 and motor 24 both of which are connected in shunt to the shutter motor iii, are

energized. The converter then energizes the ultra-violet lamp in the recirculated air stream, to irradiate the recirculated air for destroying harmful bacteria, and the motor 24 drives the air pump 26 to spray pine oil or other lated air could be employed. For example, the

motor 24 could be actuated when recirculated air is supplied, to add the pine oil, or other desired substance to the washer spray water.

While the invention has been described in connection with mechanical refrigeration, other forms of refrigeration could be employed. The usual ice source could be used and the thermostat I I could operate a by-pass around the ice water supply tank.

While one embodiment of the invention h been described for the purpose of illustration, it should be understood that other apparatus and arrangements of apparatus may be suggested by those skilled in the art without departure. from the spirit of the invention. I i

What is claimedis:

. 1. An air cooling system comprising an air cooler, means for supplying outdoor and mainculated air into said 'cooler, a thermostat excirculated air and for decreasing the proportion of outdoor air when the voutdoor temperature is above said point, means for reinvigorating the recirculatedair to simulate outdoor air conditions, and means for actuating said last mentioned means when said thermostat acts to increase the proportion of recirculated air.

- 2. An air cooling system comprising an air 50 cooler, means for supplying outdoor and recircumeans for actuating said last mentioned means when said thermostat acts to increase the proportion of recirculated air.

3. An air cooling system comprising an air cooler, means for supplying outdoor and recirculated air into said cooler, athermostat exposed to outdoor air for adjusting said means for in- 1 creasing the proportion of outdoor and for decreasing the proportion of =recirculated air when the outdoor temperature is below a predetermined point and for increasing .the proportion of recirculated air and for decreasing the proportion of outdoor air when the outdoor wet bulb temperature is above said point, means including means for adding a pleasant odor to the air for reinvigorating the recirculated air to simulate the outdoor temperature is below a predetermined point and for increasing the proportion of recirculated air and for decreasing the proportion of outdoor air when the outdoor temperature is above said point, means including an ultraviolet lamp for irradiating the recirculated air and including a device for adding a pleasant odor to the air for reinvigorating the recirculated air .to simulate outdoor air conditions, and means for actuating said last mentioned means when said thermostat acts to increase the proportion of recirculated air.

5. An air conditioner comprising a heat exchanger having an outdoor and a recirculated air inlet, an ultra-violet lamp for irradiating the recirculated air, an energizing source for said lamp, temperature responsive means for closing the recirculated air inlet, and means actuated when said temperature responsive means closes said recirculated air inlet for disconnecting said lamp from said source.

6. An air conditioner comprising a heat exchanger having an outdoor and a recirculated air inlet, an ultra-violet lamp for irradiating the recirculated air, an energizing source for said lamp, an outdoor wet bulb thermostat for closing the recirculated air inlet when the wet bulb temperature of the outdoor air falls below a predetermined polnt, and means actuated when said thermostat closes said recirculated air inlet for disconnecting said lamp from said source. I

7. An air conditioner comprising a heat exchanger having a recirculated air inlet, means for varying the volume of recirculated air entering said inlet, a device for adding a pleasant odor to the air, and means for actuating said device when said first mentioned means increases the volume of recirculated air.

8. In a heat exchanger having an outdoor air inlet, means forming a recirculated air inlet into said conditioner, adjustable means for opening and closing said recirculated air inlet, a device for adding a pleasant odor to the air, and means for actuating said device when said adjustable means opens said recirculated air inlet.

- SAMUEL M. ANDERSON. 

